Three-dimensional discrete element model of crack evolution on the crack tip with consideration of random aggregate shape

• Published in: Theoretical and applied fracture mechanics Vol. 127; p. 104022
• Main Authors: Guan, Junfeng, Zhang, Longfei, Li, Lielie, Yao, Xianhua, He, Shuanghua, Niu, Lihua, Cao, Hekai
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2023
• Subjects: Concrete; Fracture; Random aggregates; Size effect; Three-dimensional meso-models; Three-dimensional meso-models; Random aggregates; Concrete; Fracture; Size effect
• ISSN: 0167-8442; 1872-7638
• DOI: 10.1016/j.tafmec.2023.104022

•A new three-dimensional random polyhedral aggregate discrete element micro-scope fracture analysis model for concrete is developed.•The evolutionary law of three-dimensional crack extension and three-dimensional fracture process zones at concrete crack tip are investigated.•Fracture characteristics of large-size concrete specimens are predicted. In this paper, a method for concrete three-dimensional random polyhedral aggregate mesostructure is proposed. Moreover, a concrete discrete element fracture mesoscopic analysis model is established. The mesoscopic destruction mechanism of three-dimensional fracture of concrete three-point bending specimens is investigated. Three-dimensional evolutionary extension morphology of crack tip and fracture process zone (FPZ) of small-size concrete specimens in an indoor laboratory is simulated and analyzed. Furthermore, the entire fracture process of concrete specimens is investigated. The three-dimensional morphology of the crack tip and fracture process zone is analyzed via normal distribution statistics. Consequently, the size effect law of crack extension and fracture process zone evolution is derived. The fracture process of actual large-scale concrete specimens is predicted based on deficiencies of small-scale specimens in indoor tests. The results show that the proposed model is an effective method to characterize the three-dimensional fracture process of concrete and predict mechanical properties of large-scale specimens in actual structures.